Three new antimicrobial p-tert-butylcalix[4]arene derivatives were studied in a membrane environment, using 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE) and 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) monolayers; the aim of this study was getting some insight in the relation between the membrane structure and the activity of lipolytic enzymes. The derivatives used have 6-aminopenicillanic acid or benzylpenicillin moieties grafted in alternate positions at the calixarene lower rim. The miscibility of calixarene-antibiotic conjugates with lipid films was studied using surface pressure and surface potential measurements, as well as Brewster angle microscopy. Molecular modeling allowed assessing the lowest energy conformations of the calixarene derivatives and gave more insight in the interactions with the lipid films. The results obtained show that the 6-aminopenicillanic acid derivative decreases the molecule packing in the mixed films compared to the benzylpenicillin derivatives; the decreased molecule packing is accompanied by an increased ordering of the DMPE molecules in the lipid-rich phase. Moreover, the 6-aminopenicillanic acid derivative affects the activity of phospholipase A₂ (PLA₂) catalyzing the hydrolysis of the DLPC monolayer. It may be supposed that the adjustment of the activity of PLA₂ is due to the modifications of the film structure, which influences in turn the process of binding of the enzyme to the substrate surface. The results obtained in this work will be used to develop methods of a controlled enzymatic engineering of selective lipid membranes.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/12324 must be provided.

1. Selective complexation of inorganic cations with two amphiphilic calixarene derivatives in Langmuir films
2. Influence of three oxicam drugs on the properties and enzymatic lipolysis of model membranes